Power transmission device



March 7, 1939. H. SHAPIRO ET AL 2,149,873

POWER TRANSMISSION DEVICE Filed Dec. 11, 1934 2 Sheets-Sheet l 5 I {4 INVENTORS ATTORNEYS.

March 7, 1939. H. SHAPIRO ET AL POWER TRANSMISSION DEVICE 2 Sheets-Sheet 2 Filed Dec. 11, 1934 ATTORNEYS.

Patented Mar. 7, 1939 POWER TRANSMISSION DEVICE Henry Shapiro, New York, and Isaac Joffe, Brooklyn, N. Y.; said Shapiro assignor to said Jofie Application December 11, 1934, Serial No. 756,916

4 Claims. (01. 192-17) This invention relates to a new and improved power transmission device.

One of the objects of the invention is to provide a new and improved combination mot-or and able type. Said end-thrust bearing is of the the adjacent cap :8, and another plate which is freely turnable with sleeve 8. It is not necessary clutch device, which can be used as a power to fix the right-hand plate of the end-thrust transmission device for any purpose. bearing to cap 18, and said bearing may be slid Another object of the invention is to provide a into position. unit of this type which can be used conveniently The rotor l is located in the usual manner with for driving individual sewing machines, or other reference to the stator 2, and the field coils 3 are individual pieces of apparatus. conventionally shown.

Another object of the invention is to provide a female clutch member 4 has an end 4a which combined electric motor and clutch device, in is provided with the usual internal tapered face. which the rotor of the motor is permitted to idle, Said member 4a is intergral with radial arms 5a, until the transmission device becomes operative. which project from a hub 5. Said hub 5 is con- Other objects of the invention will be set forth nected to the rotor l by means of suitable bolts 6. in the following description and drawings, which Hence the female clutch member 4 and the rotor illustrate preferred embodiments thereof. turn in unison.

Fig. 1 is a sectional view, partially in elevation, The male clutch member 14 is provided with illustrating one embodiment of my invention. the usual friction ring l5, and said member H.

Fig. 2 is a sectional view through the line 2--2 is connected to the shaft 1, by one or more set of Fig. 1. screws 16 or the like.

Fig. 3 is a view similar to Fig. 1, showing a sec- The rotor I has a sleeve construction at its 0nd embodiment of the invention. inner face, and this sleeve fits turnably upon the Fig. 4 is a view similar to Fig. 1 and Fig. 3, sleeve 9. The shaft 1 is bodily shiftable in the showing a third embodiment of the invention. direction of its longitudinal axis, by means of the Referring to Fig. 1 and Fig. 2, the device is located within a suitable casing. 19, having end caps l8, which are secured to the body of the easing in any suitable manner.

A shaft 1 is mounted, so that said shaft can be moved to and fro in the direction of its longitudinal axis. For this purpose, the end caps I8 are provided with bearings 20. At its outer end, shaft 1 is provided with a pulley 21, which is connected to said shaft by means of a set screw or other suitable holding device 22. The sewing machine or other mechanism which is to be operated, can be provided with a belt which is connected to the driving pulley 2i.

In order to lubricate the device, the shaft 1 is provided with an internal recess or bore [0 at one end thereof, and a lubrication nipple N of the usual type is located at the outer end of the bore l0.

rease or other lubricant can be forced into the bore it, and said longitudinal bore l0 communicat-es with transverse bores I I. A pair of sleeves 8 and 9 are mounted upon the exterior of the shaft These sleeves 8 and 9 turn in unison with the shaft i.

As shown in l, the sleeve 9 has bores or openings which communicate with bores H of shaft '5', so that the inner sleeve surface of the rotor is weil lubricated.

The sleeve 3 is provided at one end with a head 8a, and the sleeve 9 is provided at one end with a head 9a. The right hand end of the sleeve 9 abuts the read 8a; The sleeve 8, at its right hand end, abuts an end thrust bearing B, which is provided with anti-friction members ll of any suitshift member 24, which is pivoted at 25 to an arm 26 which is connected to the adjacent end cap I 8. The shift member 24 is provided with a lug or separate member 23, which abuts the adjacent end of the shaft 1. A coil spring i2 is mounted upon the shaft 1, and said spring abuts the adjacent walls of the male clutch member l4, and of the head So. This pressure of spring l2 yieldingly maintains the sleeves 8 and 9 in the relative position shown in Fig. l, and the heads 8a and ta prevent any longitudinal shifting of the rotor and of its associated hub 5. The radial arms 5a are shaped so as to act as fan-members, so that air is drawn into the casing through holes 18 which are provided in only one of the caps I8. The air current cools the rotor and said current of air is forced out through a circumferential series of holes 49, and to a slight extent through the hole provided for brake arm 28.

According to this construction, the rotor can turn freely or idle on sleeve 9, when the clutch is inoperative. When the shift member 24 is operated, the shaft 1 is moved in the direction of its longitudinal axis, until the friction ring l5 of the male clutch member is pressed against the internal tapered surface of the female clutch member 4a. This longitudinal movement is rather slight, so that the simultaneous longitudinal shifting of the pulley 2| does not affect the belt transmission. When the clutch is coupled, the shaft I is turned in unison with the rotor. I'he shift member 24 has a brake member 28 adjustably connected thereto by means of the clamping screw 30. The brake 28 is provided with a brake-shoe 29, which normally is pressed against the outer surface of the male clutch member It. The link 21 is used for pulling down the adjacent end of the shift member 24, thus turning the same in the clockwise direction around the pivot 25. Hence the brake is released from the male clutch member, as the same is shifted, together with the shaft 1, until the clutch is operative. The sleeves 8 and 9 are not keyed to the shaft '5. However, the pressure which is produced by the spring l2 against the sleeves, when the clutch member [4 is in the operative position, may cause a certain frictional binding between said sleeves 8 and 9 and the member [4, so that the sleeves 8 and 9 and the spring I2 then turn in unison with the shaft 1.

The end thrust bearing B prevents the binding of said sleeves, so that they can turn freely in unison with shaft 1. The casing 19 is provided with brackets 31, by means of which it can be connected to the underside of the sewing machine or power bench or other means.

In the embodiment shown in Fig. 3, the casing l9 has the construction shown in Fig. 1. Fig. 3 also shows a structure, in which the shaft 1 is turnable, and it is also longitudinally movable in the direction of its longitudinal axis. A sleeve do is mounted in a suitable bore or opening of one of the caps l8, and said sleeve 40 is connected to said adjacent cap [8, by means of screws or other fastening devices 42. The shaft 1 and sleeve 48 are provided with lubricating means, of the type previously described. This lubrication system permits the interior sleeve surface of the rotor I, to turn freely relative to the sleeve.

In the embodiment shown in Fig. 3, the end thrust bearing B is located in the hub 5. The end thrust bearing is of the usual type, having plates. The hub is not connected to the adjacent thrust-bearing plate, and the sleeve 40 is likewise not rigidly connected to the adjacent plate. The pressure spring 52 keeps the plates in proper position, and the end thrust bearing also acts as a stop-collar to prevent any substan tial lateral movement of the rotor when it is coupled to the shaft. While the rotor is idling, both plates of the end-thrust bearing B remain stationary, since there is a slight lateral play between the walls of the recess of hub 5, and the plates of the end-thrust bearing. When shaft 1 is shifted, pressure is applied by the male clutch member to the female clutch member and to hub 55, so that the left-hand wall of the recess in hub 5, presses against the left-hand plate of the end-thrust bearing. Likewise spring I2 is then compressed so that it exerts additional pressure against the thrust-bearing, so that the righthand plate thereof is pressed against the end of stationary sleeve 4 Hence when the rotor turns, while the clutch is engaged, the left-hand plate turns in unison with the rotor and the right-hand plate does not turn, because it is pressed against sleeve 43.

In this embodiment, spring l2 turns with shaft I, when the rotor is coupled to the shaft,

In the embodiment shown in Fig. 4, a studshaft 1a is provided and it is non-turnable. Said stud-shaft la is rigidly connected to the casing 52, so that it is not movable in any direction relative to the casing. At one end, the stud-shaft 1a is connected to the single end cap is, by means of a clamping screw 5! or the like. The casing 52 is also provided with an arm or bracket 25c, and this bracket 26c has a sleeve 26a through which the adjacent end of the stud-shaft passes.

This sleeve 26a is also provided with a clamping screw or screws 5|, which engage the adjacent end of the stud-shaft 1a.

The sleeve '60 is mounted upon the stud-shaft 1a without being fixed thereto, and the inner sleeve surface of the rotor I, is mounted upon said sleeve 60. An end-thrust bearing B of the usual type is provided in this embodiment at the right-hand end of the rotor. Said bearing is mounted upon sleeve 60. In this embodiment, the shift member 24 is pivotally mounted at 25, to a lug 26b of the arm or bracket 26c. Said shift member is provided with a fork 6|, which presses against the adjacent end of a second or supplemental end-thrust bearing B. The hub 45 of the male clutch member [4, is mounted upon the sleeve 43, which is non-turnably mounted upon the stud-shaft 1a. The spring I2 abuts the inner or adjacent ends of sleeves 43 and 60. Lubricating means of the type previously described are provided, to permit the free axial movement of sleeve 43, the free turning of hub 45 and the free turning of rotor I on sleeve 50.

In this embodiment, when the shift member is operated, the sleeve 43 and the male clutch member l4 are shifted in unison, until the clutch members are coupled.

When the sleeve 43 is shifted the spring I2 is compressed. The sleeve 60 is not moved longitudinally when sleeve 43 is shifted, so that the shifting does not affect the free turning of rotor l. The end or longitudinal pressure on male clutch member I4 is taken up by the end-thrust bearing on sleeve 43, so that the sleeve 43 can remain non-turning while the male clutch member and its hub 45 turn on sleeve 43. The pressure of the shift member does not hinder the free turning of the male clutch member. The split drive pulley 44 has a two-part hub 46, the parts of which are connected by fastening members 47 so that said pulley is firmly connected to hub 45. Hence the sleeves 43 and 6-D can remain nonturning when the clutch is operative or inoperative. The spring l2 remains stationary in this embodiment. Hence, in all the embodiments, the spring I2 is free from torque, when the clutch is coupled. The spring l2 either turns in unison with the clutch, or said spring remains stationary.

When the male clutch member is pressed against the female clutch member, in the embodiment of Fig. 4, pressure is exerted on hub 5 and on the rotor, in the right-hand direction. This pressure is taken up by the associated end-thrust bearing on sleeve 60. There is a slight longitudinal clearance (in the direction of the axis of stud shaft 'la) between the inner-sleeve surface of the rotor and its bearing on sleeve '63, so that when the clutch is coupled, the rotor can turn without turning sleeve 60. The pressure of spring [2 exerts a braking effect on sleeve 50, so that it does not turn. The spring I2 may be under a certain compression, in all the embodiments, while the rotor is idling.

The clutch per se represents a power-transmission device which can be replaced by any other type of coupling or power-transmission device. The end-thrust bearing B on sleeve 69 prevents any binding between the rotor I and said sleeve 663, during the period that the clutch is operative, and the rotor is therefore subjected to endthrust.

It Will be noted that in all the embodiments the motor and the clutch are almost completely enclosed in a casing so that the parts are protected from dust and dirt. However, the casing may be of skeleton construction if desired, so as to substantially enclose the parts to the extent necessary to protect the operator. The pulley and belt drive can be suitably enclosed in. any well known manner so that the operator is protected from all the moving parts of the power unit.

Whenever we refer to a clutch in the claims it is to be understood that We include any power transmitting device. The pulley 2i may be designated as a power transmission element which is external to the casing.

Referring to Fig. 1 the sleeves 8 and 9 may be considered as forming a single bearing as the division of this hearing into two sleeves is for convenience of assembly. For example, in assembling the device, the left-hand cap I8 which is shown in Fig. l canbe removed, the sleeve 8 can be slid into position, the rotor I and the sleeve 9 and the member 4 can then be assembled external to the casing and slid into position, and the male clutch member 14- can then be connected to the shaft 1. If desired the male clutch member 14 can be connected to the shaft 1 while said male clutch member is external to the easing IS.

The cap l8 can be then slid into the position shown in Fig. 1. Likewise, and if it is desired to inspect or repair the device, the left-hand cap l8 can be removed, the pulley 2| and the nipple N can be removed, and the shaft 1, together with all the assembled parts can then be slid out of the casing.

Referring to Fig. 4 the cap [8 which is at the right-hand side of the casing 52 can be removed, the fastening member or members 5| can be removed, the split pulley 44 can be removed from the hub 45 and the shaft 1a, together with all the assembled parts can then be removed as a sub-assembly from the casing.

It will be noted that the left-hand wall of the casing 52 has a small opening so that the left-hand thrust bearing B can be slid through the same, but this opening is too small to permit any substantial entrance of dirt or the like.

It will be noted that when the rotor is idling, there are minimum wear and power consumption, because the shaft then remains stationary, because the rotor then turns on its independent bearing. Likewise, the unit can be lubricated from a single point.

The shaft 1 or the shaft 1a may be designated as a supporting-shaft, since it supports the weight of the rotor, even though a bearing may be located between the rotor and said supporting shaft. Since the rotor can turn relative to its supporting shaft, there is minimum power loss when the device is idling. Likewise, the rotor can turn relative to said bearing, if a bearing is used.

The member 1 which is shown in Figs. 1-3, and the member la which is shown in Fig. 4, may be designated as the primary rotor-support. That is, while the rotor is mounted directly upon the sleeve 9 which is shown in Fig. 1, for example, said sleeve 9 is supported upon the member I.

We have shown a preferred embodiment of our invention, but it is clear that numerous changes and omissions can be made without departing from its spirit.

I claim:

1. A power transmission unit comprising an electric motor having a rotor which is provided with a central opening, a shaft passing through said opening, a bearing located in said opening between said shaft and said rotor, said bearing being mounted on said shaft, a clutch having a first clutch member and a second clutch member, the first clutch member being connected to said rotor, the second clutch member being shiftable and being operatively connected to a power transmission element, a spring abutting said bearing and said second clutch member, means for shifting the second clutch member into operative relation against the force of said spring, said firstmentioned bearing having an end-thrust bearing between one end of said first-mentioned bearing and a part of the unit which is held against movement which could be produced by the force of said spring, in order to take up the force of said spring when the clutch is operative.

2. A power transmission unit comprising a. casing, an electric motor and a motor shaft located within said casing, said shaft projecting through said casing at at least one end thereof, said unit comprising a power transmission element which is mounted externally to said casing, said motor having a hollow rotor in which the shaft is located, a bearing for said rotor so that said rotor can turn independently of said shaft, said bearing being located between the motor shaft and the rotor, means for lubricating said bearing so as to lubricate the inner surface of the rotor, a clutch located within said casing and adapted to couple said rotor to said power transmission element, and a movable member for controlling said clutch, said movable member being located external to said casing and having a brake member which projects through a wall of said casing.

A power transmission unit comprising an electric motor having a rotor mounted on a primary rotor support which passes through said rotor, a sleeve loosely mounted between said primary rotor support and said rotor, said sleeve being turnable relative to said rotor support, a. first clutch member connected to the rotor, a second and turnably mounted clutch member which is mounted for longitudinal shifting movement relative to the first clutch member and which is operatively connected to a driven member, a spring normally holding said clutch members in separated and operative relation, one end of said spring abutting said sleeve.

4. A power transmission unit comprising an electric motor having a rotor mounted on a primary rotor support which passes through said rotor, a first sleeve loosely mounted between said rotor and said primary rotor support, said first sleeve passing through said rotor, means to supply lubricating material between said primary rotor support and said first sleeve, a first clutch member connected to the rotor, a second and turnably supported clutch member which is mounted for longitudinal shifting movement relative to the first clutch member and operatively connected to a driven member, a second sleeve which is turnable relative to said second clutch member and located between said second clutch member and said primary rotor support, a spring normally holding said clutch members in separated and inoperative relation, said spring being located between said clutch members, one end of said spring abutting said first sleeve and the other end abutting said second sleeve.

HENRY SHAPIRO. ISAAC JOFFE. 

